Cerebral blood flow (CBF), cerebral oxygen delivery, and intracranial pressure were measured in 12 dogs subjected to hemorrhagic shock and then resuscitated with lactated Ringer's solution or 6% hetastarch. Hemorrhagic shock was produced by the rapid removal of blood to achieve a mean arterial pressure (MAP) of 40 mm Hg with BP maintained at that level for 30 min. Six animals were resuscitated with lactated Ringer's solution, 60 ml/kg iv, and six with 6% hetastarch, 20 ml/kg iv. Both solutions effectively restored systemic hemodynamic stability, increasing cardiac output and MAP. Intracranial pressure was significantly (p < .05) lower after resuscitation in the hetastarch group, but CBF, which had decreased during shock, was not normalized by either fluid, and cerebral oxygen transport fell further with resuscitation secondary to a hemodilutional reduction of hemoglobin. Although 6% hetastarch may improve systemic hemodynamics and maintain a low intracranial pressure during resuscitation, it fails, as does lactated Ringer's solution, to restore cerebral oxygen transport to prehemorrhagic shock levels.
ASJC Scopus subject areas
- Critical Care and Intensive Care Medicine